Show simple item record

dc.contributor.advisorSchotland, Richarden_US
dc.contributor.authorPOST, MADISON JOHN.
dc.creatorPOST, MADISON JOHN.en_US
dc.date.accessioned2011-10-31T18:55:59Zen
dc.date.available2011-10-31T18:55:59Zen
dc.date.issued1985en_US
dc.identifier.urihttp://hdl.handle.net/10150/187935en
dc.description.abstractThis work describes the design, implementation, and calibration of NOAA's coherent, pulsed, Doppler lidar. This lidar was used to acquire 252 high quality, independent measurements of atmospheric backscattering profiles from 4 to 30 km altitude over Boulder, Colorado, at a wavelength of 10.6 micrometers between May 1981 and May 1983, a period that includes the injection and removal of debris from the El Chichon eruptions. Statistical analyses of the data set by computer show that atmospheric backscattering is approximately lognormally distributed for all but the lowest altitudes, and a theoretical explanation is offered for this property. Seasonally-averaged profiles and altitudinally-stacked, filtered time sequences show the volcanic cloud appearing in the stratosphere and falling through the tropopause into the troposphere at rates far higher than can be explained by gravitational settling alone. The dynamic process of tropopause folding is proposed as the dominant mechanism for the observed exchange of volcanic debris from the stratosphere to the troposphere. This hypothesis is supported by case studies of mid-tropospheric backscatter-enhancing events. Mie calculations and comparisons with other measurements show that vertically-integrated backscatter is a good long-term measure of total atmospheric mass loading of volcanic debris. It is found that the time constant which characterizes debris removal is 208 days for the stratosphere and 60 days for the troposphere. No appreciable debris is removed before the volcanic cloud falls to 6 km altitude 420 days after the volcanic eruptions.
dc.language.isoenen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.subjectBackscattering.en_US
dc.subjectAtmospheric physics -- Measurement.en_US
dc.subjectTroposphere.en_US
dc.titleATMOSPHERIC INFRARED BACKSCATTERING PROFILES: INTERPRETATION OF STATISTICAL AND TEMPORAL PROPERTIES.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.identifier.oclc693610285en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.identifier.proquest8512686en_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePh.D.en_US
refterms.dateFOA2018-06-26T12:51:38Z
html.description.abstractThis work describes the design, implementation, and calibration of NOAA's coherent, pulsed, Doppler lidar. This lidar was used to acquire 252 high quality, independent measurements of atmospheric backscattering profiles from 4 to 30 km altitude over Boulder, Colorado, at a wavelength of 10.6 micrometers between May 1981 and May 1983, a period that includes the injection and removal of debris from the El Chichon eruptions. Statistical analyses of the data set by computer show that atmospheric backscattering is approximately lognormally distributed for all but the lowest altitudes, and a theoretical explanation is offered for this property. Seasonally-averaged profiles and altitudinally-stacked, filtered time sequences show the volcanic cloud appearing in the stratosphere and falling through the tropopause into the troposphere at rates far higher than can be explained by gravitational settling alone. The dynamic process of tropopause folding is proposed as the dominant mechanism for the observed exchange of volcanic debris from the stratosphere to the troposphere. This hypothesis is supported by case studies of mid-tropospheric backscatter-enhancing events. Mie calculations and comparisons with other measurements show that vertically-integrated backscatter is a good long-term measure of total atmospheric mass loading of volcanic debris. It is found that the time constant which characterizes debris removal is 208 days for the stratosphere and 60 days for the troposphere. No appreciable debris is removed before the volcanic cloud falls to 6 km altitude 420 days after the volcanic eruptions.


Files in this item

Thumbnail
Name:
azu_td_8512686_sip1_w.pdf
Size:
3.588Mb
Format:
PDF

This item appears in the following Collection(s)

Show simple item record